Defensive publication

ABSTRACT

A PROCESS FOR SKIVING A SHAPED ARTICLE SUCH AS A CYLINDRICAL BLANK OF AROMATIC POLYIMIDE POLYMERIC MATERIAL IS PROVIDED WHEREIN IN CYLINDRICAL BLANK OF POLYIMIDE SUCH AS POLY N,N-(4,4&#39;&#39;-OXYDIPHENYLENE) PYROMELLITIMIDE IS MOUNTED ON A LATH AND ROTATED AT A CONSTANT SPEED, E.G. 20. R.P.M. AND THEN HEATED TO, FOR EXAMPLE. 250*C. A HEATED SKIVING KNIFE IS BROUGHT INTO CONTACTING RELATIONSHIP WITH THE SURFACE OF THE POLYIMIDE CYLINDER SO THAT THE KNIFE CONTACTS THE CYLINDER AT AN ANGLE OF BETWEEN ABOUT 5* AND ABOUT 20*. A STRIP IS SKIVED FROM THE POLYIMIDE CYLINDER WHILE MAINTAINING THE TEMPERATURE OF THE SKIVING KNIFE AND THE TEMPERATURE OF THE SURFACE OF THE POLYIMIDE CYLINDER AT BETWEEN ABOUT 250*C. AND ABOUT 500*C.

DEFENSIVE UBLICATION UNITED STATES PATENT OFFICE Published at therequest of the applicant or owner in accordance with the Notice of Dec.16, 1969, 869 0.6. 687. The abstracts of Defensive Publicationapplications are identified by distinctly numbered series and arearranged chronologically. The heading at each abstract indicates thenumber oi? pages of specification, including claims and sheets ofdrawings contained in the application as originally filed. The files ofthese applications are available to the public for inspection andreproduction may be purchased for 30 cents a sheet.

Defensive Publication applications have not been examined as to themerits oil alleged invention. The Patent Oflice makes no assertion as tothe novelty of the disclosed subject matter.

PUBLISHED AUGUST 31, 1971 T889,026 SKIVING AROMATIC POLYIMIDE SHAPESFrank Clyde Starr, Jr., Wilmington, Del., assignor to E. L

du Pont de Nemours and Company, Wilmington, Del. Continuation ofapplication Ser. No. 711,487, Mar. 8,

1968. This application Oct. 28, 1970, Ser. No. 84,872

Int. Cl. B29d 7/18, 7/24 U.S. Cl. 264-158 No Drawing. 9 PagesSpecification A process for skiving a shaped article such as acylindrical blank of aromatic polyimide polymeric material is providedwherein the cylindrical blank of polyimide such aspoly-N,N-(4,4'-oxydiphenylene) pyromellitimide is mounted on a lath androtated at a constant speed, e.g. 20 r.p.m. and heated to, for example,250 C. A heated skiving knife is brought into contacting relationshipwith the surface of the polyimide cylinder so that the knife contactsthe cylinder at an angle of between about 5 and about 20. A strip isskived from the polyimide cylinder while maintaining the temperature ofthe skiving knife and the temperature of the surface of the polyimidecylinder at between about 250 C. and about 500 C.

20. R.P.M. AND THEN HEATED TO, FOR EXAMPLE. 250*C. A HEATED SKIVINGKNIFE IS BROUGHT INTO CONTACTING RELATIONSHIP WITH THE SURFACE OF THEPOLYIMIDE CYLINDER SO THAT THE KNIFE CONTACTS THE CYLINDER AT AN ANGLEOF BETWEEN ABOUT 5* AND ABOUT 20*. A STRIP IS SKIVED FROM THE POLYIMIDECYLINDER WHILE MAINTAINING THE TEMPERATURE OF THE SKIVING KNIFE AND THETEMPERATURE OF THE SURFACE OF THE POLYIMIDE CYLINDER AT BETWEEN ABOUT250*C. AND ABOUT 500*C.